System for recovering downhole oil and gas from economically nonviable wells

ABSTRACT

An improved system of increasing downhole oil or gas production in otherwise economically nonviable oil or gas wells. The present system cycles compressed atmospheric gas either through a primary well alone, or through both surrounding wells and a primary well. System components are configured so as to provide for especially cost effective and environmentally friendly operation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed towards an improved oil or gasrecovery system. Said system is particularly useful for increasing theefficiency of low producing oil or gas wells through the use ofcompressed atmospheric gas to displace downhole oil or gas. Benefitsprovided by applicant's invention include: enhanced recovery of oil orgas which would otherwise be unrecoverable, increased production ofexisting wells, elimination of the need to drill additional oil or gaswells as a result of nominal or no economic viability.

2. Background Information

Fossil fuels, particularly oil, are the number one source of energyglobally. The role of oil or gas in the world's energy and petrochemicalmarkets in the present global economy cannot be overstated. Thediscovery of and efficient harvesting, or production of oil or gascommodities, has a major impact in the operation of our modern economy.In fact, the department of energy estimates that only approximately tento twenty percent of oil or gas from known reservoirs is recoverablewithout using some form of enhanced production technology.

Production enhancement is essential to harvest as much of the remaining,otherwise unrecoverable eighty percent of oil or gas reserves.Production enhancement has been used for the past 50 years to increaseproduction. As such, new techniques are at a premium in order toincrease production at lower prices. As will be discussed in thespecification to follow, applicant's invention provides acost-effective, efficient means for producing otherwise nonviabledownhole oil or gas in view of known systems.

The first enhanced production technique involved injecting salt waterinto the reservoir to increase pressure, displace oil or gas, and drivemore oil or gas to the surface of the well. Additional techniquesfollowed including the injection of steam. The injection of steam isoften used to increase recovery of highly viscous oil that wouldotherwise not easily flow well through rock. The next technique is theinjection of chemical polymers, which like detergents, act assurfactants that lower the surface tension of oil. Such a reactionfacilitates oil movement through pores and fissures in the reservoir.

Finally, the use of pressurized gas, carbon dioxide in particular, hasbeen used much like the production enhancement of salt water. By pumpingcarbon dioxide into the well, increased pressure improves theperformance of the well by driving oil through the pores in the rock andto the existing well. The use of carbon dioxide has distinct advantagesover the use of water, steam, and polymers in that it is cheaper.Nevertheless, the use of carbon dioxide to recover oil or gas is limitedin view of applicant's present invention. For instance, the use ofcarbon dioxide injections systems are limited in application by theavailability of a carbon dioxide source. Typically, the carbon dioxideused is byproduct gas of industrial origin. However, in the absence of anearby source of carbon dioxide, it would either need to be producedon-site or transported to the injection site Either way, there is greatexpense in view of applicant's invention.

There is a great need for an economical, efficient, and environmentallyfriendly technique to increase oil production from otherwise non-viablewells. Drilling additional oil or gas wells will not solve the problemsince oil or gas may be trapped in isolated pockets below the surface.In such case, the cost of additional wells would exceed the benefit ofrecovering marginal amounts of oil or gas. Cumulatively, however, theseotherwise difficult or unrecoverable oil or gas pockets may constitute alarge percentage of the oil or gas reservoir. Presently existingtechnologies currently are unable to produce the full potential of oilor gas reservoirs in a economically viable and environmentally friendlymanner.

Distinguished from the prior art, the present invention injectspressurized atmospheric gas into both principal wells and surroundingwells. Applicant's invention is capable of pressurizing the primary wellsite by injection compressed air particularly in the primary wellhead,or, by injection of compressed air in surrounding, related wells. Assuch, the present invention is particularly effective in producing oilor gas embedded within mineral resources, fissures, and othernon-economically nonviable locations outside of the primary well.Moreover, the use of compressed air rather than carbon dioxide, othergasses, or salt water is less expensive because of the availability ofatmospheric gas at the wellhead location. As such; no transportation ofmaterials to the injection site is required. Further, applicant'sinvention does not pose the risk of environmental contamination throughthe injection of foreign substances into the ground. Finally,applicant's invention is extremely cost-effective, that is, use ofatmospheric air is a resource limited only by the number of compressionpumps and poses no risk of subsoil contamination by polymers or brine.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the present invention toprovide an improved oil and gas recovery system that is economicallyviable.

It is another object of the present invention to provide an improved oiland gas recovery system that increases oil or gas production from lowproducing wells.

It is another object of the present invention to provide an improved oiland gas recovery system that uses readily available atmospheric aircompressed and injected into locations surrounding existing oil or gaswells to drive oil or gas from non-producing or economically non-viablelocations to the existing well.

It is another object of the present invention to provide an improved oiland gas recovery system that injects readily available compressedatmospheric air into low-producing wells to increase well pressure andincrease production.

It is another object of the present invention to provide an improved oiland gas recovery system that extracts otherwise lost mineral resourcesin a manner which when employed does not have a detrimental effect onthe environment.

It is another object of the present invention to provide an improved oiland gas recovery system that is efficient.

It is another object of the present invention to provide an improved oiland gas recovery system that is environmentally friendly.

It is yet another object of the present invention to provide an improvedoil and gas recovery system that is cost-effective in view of systemsknown in the art.

In satisfaction of these and related objectives, and as will be furtherdiscussed in the specification to follow, practice of the presentinvention involves a surface-based air compressor whereby saidcompressor takes in atmospheric gas, compresses the gas, and cycles thepressurized gas through a downhole well bore.

In particular embodiments of the present system, compressed gas may becycled though a surrounding or secondary well bore, or a primary wellbore. That is, an embodiment of the present system provides compressedair to be pumped into a bore separated from the production bore by aregion of rock containing pores or fissures. As the air pressure of thesecondary well and intermediate rock region increases, embeddedproduction oil or gas is forced out of the pores or fissures in thedirection from high pressure to low pressure. Finally, as the pressureincrease reaches the primary well, oil or gas is assisted up through anin-place production shaft. Alternatively, the surface based pump may beplaced above a well bore that shares the same well as the productionwell bore. In such case, downhole well pressure is directly increased ascompressed air is cycled through the well.

Further embodiments of the present invention incorporate the use of avacuum pump, located at the surface. Said pump may be used alone, or inconjunction with the surface air compressor to further assist therecovery process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross section view of the system of the present inventionwhere compressed air is cycled through both a secondary and primarywell.

FIG. 2 is a cross sectional view of the system of an alternativeembodiment of the present system where an air hose is extends to adownhole well.

FIG. 3 is a cross section view of the system of the present inventionwhere compressed air is directly cycled though a primary well.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to figure one, the system of the present invention isgenerally referred to by the reference numeral 10. Air compressor 12rests on ground surface 14. In the preferred embodiment, air compressor12 is a compressor of the reciprocating-type, such as model 4D21, madeby Peter Brother Ltd. However, other useful embodiments of the presentinvention may incorporate use of standard air compressors known in theart. For example, air compressor 12 may be of the rotary, or centrifugaltype compressors. These air compressors typically are powered bycombustible fuel such as diesel or gasoline, the exhaust of which may beintermixed with the atmospheric air and pumped back into the injectionsite.

As seen in FIG. 1, air compressor 12 is aligned with surrounding orsecondary bore 16. Compressor 12 is positioned with respect to secondarybore 16 so that air may be pumped down and through bore 16. In thepreferred embodiment, compressor 12 is placed within a proximity of bore16 so that compressor 12 may be directly mated with secondary bore 16where a fluid-tight seal is formed at surface 14. In an alternative, yetuseful embodiment, shown in FIG. 2, an air hose 18 is engaged withcompressor 12 at air hose top end 20 and extends through secondary bore16 where an air hose second end 22 is left in an open-endedconfiguration.

Referring principally to FIG. 1, secondary well 24 is separated fromprimary well 26 by a region of porous rock or fissure 28. Operation ofthe present invention is initiated as air compressor 12 compressesatmospheric gas and sends it through secondary bore 16. Compressedatmospheric gas increases the pressure in secondary well 24 and therebyforces embedded oil or gas contained in porous region 28 into primarywell 26. As pressure increases throughout secondary well 24 and porousrock region 28, the pressure increases in primary well 26. Finally, anincreased pressure level within primary well 26 assists in oil or gasbeing forced upward through primary bore 30. In the preferredembodiment, a surface pump 32 utilizes primary bore 30, which is astandard surface pump as known in the art.

Referring to FIG. 3, an alternative embodiment of the system of thepresent invention is shown. Specifically, air compressor 12 is placeddirectly over the primary oil or gas well 26, and pumps compresseddirectly into a low-producing, low-pressure well 26 to increaseproduction by raising the pressure of the reservoir 26, making it moreeconomically efficient to capture remaining oil or gas within well 26

Yet another embodiment is characterized by the employment of vacuum pump40. In this embodiment vacuum pump 40 is placed at the surface, above asecondary or primary well. Vacuum pump 40 then creates a vacuum throughthe well shaft and along the well itself, further assisting the recoveryprocess.

Although the invention has been described with reference to specificembodiments, this description is not meant to be construed in a limitedsense. Various modifications of the disclosed embodiments, as well asalternative embodiments of the inventions will become apparent topersons skilled in the art upon the reference to the description of theinvention. It is therefore contemplated that the appended claims willcover such modifications that fall within the scope of the invention.

1. An improved downhole oil or gas recovery system, comprising an aircompressor, wherein said air compressor is a surface based pump havingan input and an output whereby atmospheric gas is cycled from said inputto said output, where said output is reversibly mated with a shaft so asto form a fluid-tight seal, and where compressed air is cycled from saidoutput through said shaft, an oil or gas well connecting means, whereinsaid oil or gas well connecting means is reversibly mated with said aircompressor at a first end, and a oil or gas well connecting means secondend extends to an oil or gas well, a surface recovery means, whereinsaid surface recovery means recovers production oil or gas from aprimary oil or gas well to said surface.
 2. A method of recoveringdownhole oil or gas, comprising the steps of selecting:
 1. An improveddownhole oil or gas recovery system, comprising an air compressor,wherein said air compressor is a surface based pump having an input andan output whereby atmospheric gas is cycled from said input to saidoutput, where said output is reversibly mated with a shaft so as to forma fluid-tight seal, and where compressed air is cycled from said outputthrough said shaft, an oil or gas well connecting means, wherein saidoil or gas well connecting means is reversibly mated with said aircompressor at a first end, and a oil or gas well connecting means secondend extends to an oil or gas well, a surface recovery means, whereinsaid surface recovery means recovers production oil or gas from aprimary oil or gas well to said surface.
 3. The improved downhole oil orgas recovery system of claim 1, further comprising a vacuum pump placedat a ground surface, attached to said oil or gas well connecting meansor said surface recovery means.
 4. The method of recovering downhole oilor gas of claim 2, further comprising the step of selecting a vacuumpump placed at a ground surface, attached to said oil or gas wellconnecting means or said surface recovery means.